Method for operating a well jet device during repair and insulating operations and device for carrying out said method

ABSTRACT

The inventive method consists in the following: a drillable packer provided with a channel closed by a back valve is arranged in a well; afterwards a tubing string carrying a jet pump and a stinger is run into said well, the stringer being connected to the packer; the back valve is open; a logging instrument and a sealing unit are introduced into the tubing string with the aid of a cable; a depression is produced on the formation by means of the pump, a bottomhole pressure and the parameters of the formation are measured with the aid of said instrument, the parameters of physical fields being recorded. The results of said investigations being interpreted, the technical state of the well is defined. The instrument and the sealing unit being extracted from the tube string, a blocking insert is dropped therein. The tubing string is uplifted, the stringer is disconnected from the packer and the back valve is closed. A cement slurry being pumped into the tubing string, said tubing string is put down, the stringer is connected to the packer and the back valve is open. The cement slurry is pumped into the tail space, squeezed into the productive formation and the tubing string together with the pump and the stringer is extracted. The cement slurry being hardened, the packer is drilled out, the formation is perforated and the tubing string provided with a guiding cone, the packer and the pump is brought in the well. Said invention increases the reliability of the repair and insulating operations.

FIELD OF THE INVENTION

This invention relates to the field of jet equipment, mainly to well jetunits used while carrying out restoration and repair and insulatingworks in wells.

PRIOR ART

Known in the art is a method of operating a well jet unit, whichincludes lowering the piping string with a jet pump, a packer and apuncher into the well, arranging the puncher against the producingformation and blasting the puncher with subsequently pumping the liquidworking medium through the jet pump (SU 1146416 A).

Known from the same source is a well jet unit comprising a piping stringwith a jet pump, a packer and a puncher, the latter being arranged belowthe jet pump and against the producing formation.

The known method and unit enable to perforate boreholes at a setdepression value and pump out of the well different extracted media,e.g., oil, while simultaneously intensifying the medium production outof the formation.

But the said method and unit do not enable to install the productionequipment in the well below the jet pump as well as to replace thelatter in the process of operation without packer releasing in thepiping string, which lowers the efficiency of the well developmentoperations.

The closest, as to its technical essence and the achievable result, tothis invention in the part of the method is a method of operating a welljet unit, which comprises lowering a jet pump and a packer on the pipingstring and installing them above the producing formation, lowering atransmitter and receiver-transducer of physical fields on a cable, thesaid cable being passed through a sealing assembly arranged thereon, andcreating depression on the formation with the use of the jet pump (RU2129671 C1).

The known method of operating a well jet unit enables to carry outvarious production operations in the well below the level at which thejet pump is arranged, including those carried out by creating pressuredifferential above and below the sealing assembly.

But the said method of operating the unit does not enable to carry outthe complete complex of works on exploring and restoring wells, whichnarrows its field of application.

The closest, as to its technical essence and the achievable result, tothis invention in the part of the device is a well jet unit comprisinginstalled on the piping string a packer a jet pump with the activenozzle, the mixing chamber and a through passage having the mountingseat for installing a sealing assembly, the said unit being providedwith a transmitter and receiver-transducer of physical fields, which isarranged in the area below the packer on the side of entry of thepumped-out medium into the jet pump and installed on the well-loggingcable passed through the axial passage of the sealing assembly, theoutput side of the jet pump being connected to the area around thepiping string, the input side of the passage for supplying thepumped-out medium to the jet pump being connected to the inner cavity ofthe piping string below the sealing assembly, and the input side of thepassage for supplying the liquid working medium to the active nozzlebeing connected to the inner cavity of the piping string above thesealing assembly (RU 2059891 C1).

The known well jet unit enables to carry out various productionoperations in wells below the level at which the jet pump is arranged,including those carried out by creating pressure differential above andbelow the sealing assembly.

But the said unit does not enable to carry out the complete complex ofworks on exploring and restoring wells, which narrows its field ofapplication.

DESCRIPTION OF THE INVENTION

The objective of this invention is to raise the reliability of repairand insulating works carried out with the use of a well jet unit onaccount of expanding the capabilities of the unit and optimizing theoperations carried out in wells.

The stated objective in the part of the method is achieved owing to thefact that the method of operating a well jet unit while carrying outrepair and insulating works comprises prior arranging in the well, abovethe producing formation roof, a drillable packer having a throughpassage, the throat of the latter being closed by a check valve,lowering in the well the piping string with a jet pump and a stingershank, which are successively arranged thereon, the said jet pump beingarranged in the housing in which a through passage with the mountingseat is made, and the said stinger shank being arranged below the saidhousing and being intended for slip connection with and disconnectionfrom the said drillable packer; then the stinger shank is connected withthe drillable packer, the check valve opens thus connecting theunder-packer area with the inner cavity of the piping string; then awell logging device on the logging cable is lowered into the wellthrough the inner cavity of the piping string, a sealing assembly beingmovably arranged on the logging cable above the said well logging deviceand being installed at the mounting seat in the through passage made inthe housing of the jet pump; in doing this the reciprocal motion of thelogging cable is ensured both at the operating and non-operating jetpump; after the well logging device has reached the interval of theproducing formation, it is installed in a fixed position, and bysupplying the working fluid to the nozzle of the jet pump several valuesof depression on the formation are created with the duration sufficientfor stabilizing the bottom-hole pressure and enabling the inflow offluids from the formation; the bottom-hole pressure and the parametersof the formation fluid are registered in this operation mode with theuse of the well logging device, after which the parameters of thephysical fields are recorded at several fixed values of the depressionon the formation while moving the well logging device along the well inthe under-packer area; and after the study program is completed theobtained results are interpreted, the results of such interpretation areused for the identification of the watering sources and the technicalcondition of the well; then, the well logging device with the sealingassembly are removed out of the well, and, if necessary, geo-technicalmeasures, such as acid treatments, formation impacting with momentarycyclic depressions - repressions, formation re-shots, acoustic impact onthe formation bottom-hole area in the depression mode, all of which areaimed at the creation of the necessary hydrodynamic connection betweenthe formation and the well and are carried out with the use of the jetpump; then the study cycle is repeated with the use of the well loggingdevices in the mode of depression on the formation; then the welllogging device together with the sealing assembly is removed out of thewell, and a blocking insert having a through passage is dropped into theinner cavity of the piping string and arranged in the through passage ofthe jet pump housing, the said blocking insert being used for closingthe passages for supplying the active medium and the medium pumped outby the jet pump and, thus, for separating the hole clearance and thecavity inside the piping string; after this the piping string isslightly raised, thus disconnecting the whole arrangement from thepacker, closing the check valve and dividing, due to this, the wellspace into the above-packer area and the under-packer area; then agrouting mortar is pumped into the piping string and, after it reachesthe lower portion of the stinger shank, the piping string is loweredagain, the stinger shank is connected to the drillable packer and thecheck valve opens; then the grouting mortar is pumped into theunder-packer area for peening into the producing formation; then thepiping string together with the jet pump and the stinger shank areremoved out of the well, and after expiration of the calculated time forgrouting mortar hardening the packer and the cement bridge formed in theresult of the grouting mortar hardening are drilled, the formation isperforated in the calculated range of depths, and the piping string islowered into the well with a shank having the guiding cone, the packerand the jet pump having the through passage with the mounting seat inits housing, all of them being arranged down-top on the piping string;after this the packer is released, and the whole cycle of logging andhydrodynamic studies is carried out proceeding from the results of whicha decision is taken whether to put the well into operation or to conductadditional studies or works for intensifying the well production; andafter this the measures for putting the well into operation may beperformed.

The stated objective in the part of the device is achieved owing to thatthe well jet unit comprises, on the piping string, the packer and thejet pump with the active nozzle, the mixing chamber and the throughpassage with the mounting seat for arranging the sealing assembly, theunit being provided with the transmitter and receiver-transducer ofphysical fields, which is arranged in the under-packer area on the sidewhere the medium pumped out of the well enters the jet pump and which isinstalled on the logging cable passed through the axial passage of thesealing assembly, the output side of the jet pump is connected to thearea around the piping string, the input side of the passage forsupplying the pumped out medium to the jet pump is connected to theinner cavity of the piping string below the sealing assembly, and theinput side of the passage for supplying the liquid working medium to theactive nozzle is connected to the inner cavity of the piping stringabove the sealing assembly; the unit being provided with the stingershank intended for slip connection with and disconnection from thedrillable packer preliminary arranged in the well and made with thethrough passage and the check valve closing the throat of that passageand having the possibility of opening to the side of the producingformation; the packer is made with a central passage and a shank withthe guiding cone, being arranged lower than the packer, and is arrangedwith the possibility of being replaced by the stinger shank, the innerdiameters of the stinger shank and the shank with the guiding cone areat least 1 mm greater that the diameter of the transmitter and thereceiver-transducer of physical fields; the sealing assembly is arrangedwith the possibility of being replaced by other functional inserts, suchas, a blocking insert, a pressurizing insert, a depression insert or aninsert for recording formation pressure restoration curves with the useof autonomous well instruments; and the transmitter andreceiver-transducer of physical fields is made with the possibility ofbeing replaced by other well instruments, e.g., a puncher or a devicefor acoustically impacting the producing formation.

In the course of the studies conducted it has been established that thecarrying out of the production operations in wells with the use of thewell jet unit in the defined succession and with auxiliary equipmentenables to raise the reliability of repair works in the well to a greatextent. The arrangement in the well of a drillable packer having athrough passage and a check valve in combination with the arrangementthe well jet unit above the said packer has enabled to expand thepossibilities of dividing the well space. The possibility is provided ofseparating not only the above-packer area from the under-packer area,but also the space around the piping string from the inner cavity of thepiping string, the said separation being possible in variouscombinations, which enables to expand the possibilities of both studyingand repairing the well. The inventive proposal enables to combine in thesingle production cycle seemingly not interconnected works, such ascreation of different depressions and repressions on the formation,supply of a grouting mortar into the well, acid treatment of the welland perforation of the well. In the result the optimal technologicalchain of operations has been selected in order to study the well afterarranging a drillable packer therein, which includes the registration ofbottom-hole pressure and the formation fluid parameters at severalvalues of depression on the formation, such studies being conducted bothat the operating and non-operating jet pump while moving the welllogging instrument—transmitter and receiver-transducer of physicalfields—along the well. Further, on the basis of the data thus obtainedthe possibility has been provided to conduct strictly defined works onimproving the hydrodynamic connection between the producing formationand the well, where such works may include acid treatment of the well,acoustic impact on the formation and re-shots of the formation (carryingout the works on perforating the formation by blasting pyrotechnicdevices). Moreover, the possibility has been provided to carry out theworks on putting wells into the operation mode, which include supply ofa grouting mortar (preferably a cement slurry) into the well, drillingof the hardened grouting mortar and the drillable packer and perforationof the formation. After this is possible to arrange in the well a welljet unit having a packer and a shank with the guiding cone to be used inthe future both for conducting further studies of the well and carryingout works on raising the well production and for operating it with apump for forced production of, e.g., oil, which is installed above thepacker. The making of the inner diameter of the stinger shank and thatof the shank with the guiding cone at least 1 mm greater than thediameter of the transmitter and receiver-transducer of physical fieldsenables to reduce the probability that logging and other instrumentslowered to the area of the producing formation may get stuck in theabove mentioned shanks, which raises the reliability of operating thewell jet unit.

Thus, the unit, as described above, enables to perform a certainsuccession of actions and create a reliable method of operating the welljet unit when carrying repair and insulating works in wells.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of the well jet unit at the time oflowering the piping string with the jet pump and the stinger shank.

FIG. 2 is a schematic representation of the well jet unit at the time oflowering the well logging device after the stinger shank has beenarranged in the drillable packer.

FIG. 3 is a schematic representation of the well jet unit with the jetpump and a blocking insert arranged in the said pump.

FIG. 4 is a schematic representation of the well jet unit at the time ofdrilling the cement bridge and the drillable packer.

FIG. 5 is a schematic representation of the well jet unit after thearrangement of the piping string together with the jet pump, the packerand the shank having the guiding cone.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The inventive well jet unit for implementing the described methodcomprises a drillable packer 1, which has been arranged in advance inthe well above the producing formation 21, with the through passage 2,which throat is closed by a check valve 3 being capable of opening tothe side of the producing formation, and the piping string 4, on whichthe jet pump 5 and the stinger shank 6 are arranged successively. Thejet pump 5 with the active nozzle 13 is provided with the housing 7, inwhich the through passage 8 with the mounting seat 9 is made, the outputside of the jet pump 5 is connected to the area around the piping string4, the input side of the passage for supplying the pumped out medium 17to the jet pump 5 is connected to the inner cavity of the piping string4 below the sealing assembly 12, and the input side of the passage forsupplying the liquid working medium 16 to the active nozzle 13 isconnected to the inner cavity of the piping string 4 above the sealingassembly 12. The stinger shank 6 is arranged below the housing 7 of thejet pump 5 and is intended for slip connection with and disconnectionfrom the drillable packer 1. The well logging device 11—a transmitterand receiver-transducer of physical fields—may be lowered into the wellon the logging cable 10 (a wire may be used instead of the loggingcable) passed through the axial passage 24 in the sealing assembly 12.The sealing assembly 12 is arranged at the mounting seat 9 in thethrough passage 8 made in the housing 7 of the jet pump 5 with ensuringthe reciprocal movements of the logging cable 10 both at the operatingand non-operating jet pump 5. Instead of the sealing assembly 12 in thethrough passage 8, at the mounting seat 9 the blocking insert 14 may bearranged, which has the through passage 15 and closes the passages forsupplying the liquid working (active) medium 16 and the pumped outmedium 17 to the jet pump 5, thus separating the space around the pipingstring 4 from the inner cavity of the piping string 4. The packer 1 andthe cement bridge 22 may be drilled with the use of the drill bit 18.After drilling, the shank 19 with the guiding cone 23, the packer 20with the central passage and the jet pump 5 having the through passage 8with the mounting seat 9 in its housing 7 may be arranged down-top onthe piping string 4. The inner diameter D₁ of the stinger shank 6 andthe inner diameter D₂ of the shank 19 with the guiding cone 23 are atleast 1 mm greater that the diameter D₃ of the transmitter and thereceiver-transducer of physical fields 11.

The described method of operating the well jet unit while carrying outrepair and insulating works is implemented as follows.

First, in the well, above the roof of the producing formation 21, adrillable packer 1 is arranged, which has the through passage 2 and thecheck valve 3 closing the throat of the said through passage. Then thepiping string 4 is lowered into the well with the jet pump 5 and thestinger shank 6, which are successively arranged on the piping string 4.After this the stinger shank 6 is connected with the drillable packer 1,and the check valve 3 opens thus connecting the under-packer area withthe inner cavity of the piping string 4. Then the well logging device 11is lowered on the logging cable 10 into the well through the innercavity of the piping string 4 with the sealing assembly 12 movablyarranged on the logging cable 10 and installed at the mounting seat 9 inthe through passage 8 made in the housing 7 of the jet pump 5 whileensuring the reciprocal motion of the logging cable 10 both at theoperating and non-operating jet pump 5. After the well logging device 11has reached the interval of the producing formation 21 it is installedin a fixed position, and by supplying the working fluid to the nozzle 13of the jet pump 5 several values of depression on the formation 21 arecreated with the duration sufficient for stabilizing the bottom-holepressure and enabling the inflow of fluids from the formation 21, thebottom-hole pressure and the parameters of the formation fluid areregistered in this operation mode with the use of the well loggingdevice 11. Then the parameters of the physical fields are recorded atseveral fixed values of the depression on the formation 21 while movingthe well logging device 11 along the well in the under-packer area.After the study program is completed the obtained results areinterpreted, the results of such interpretation are used for theidentification of the watering sources and the technical condition ofthe well; then, the well logging device 11 with the sealing assembly 12are removed out of the well. Then, if necessary, geo-technical measuresare carried out through the jet pump 5 for the purpose of creating thenecessary hydrodynamic connection between the formation and the well,such as acid treatments, impact with momentary cyclicdepressions—repressions on the formation 21, re-shots of the formation21, acoustic impact on the bottom-hole area of the formation 21 in thedepression mode, etc., and the study cycle is repeated with the use ofthe well logging devices 11 in the mode of depression on the formation21. Then the well logging device 11 together with the sealing assembly12 is removed out of the well, and the blocking insert 14 having thethrough passage 15 is dropped into the inner cavity of the piping string4 and arranged in the through passage 8 in the housing 7 of the jet pump5, the said blocking insert 14 being used for closing the passages 16,17 for supplying the liquid working (active) medium and the mediumpumped out by the jet pump 5 and, thus, for separating the clearancearound the piping string 4 and the cavity inside the piping string 4.After this the piping string 4 is slightly raised, thus disconnectingthe stinger shank 6 from the packer 1, closing the check valve 3 anddividing, due to this, the well space into the above-packer area and theunder-packer area. Then a grouting mortar (e.g., a cement slurry) ispumped into the piping string 4 and, after it reaches the lower portionof the stinger shank 6, the piping string 4 is lowered again, thestinger shank 6 is connected to the packer 1 and the check valve 3opens. Then the piping string 4 together with the jet pump 5 and thestinger shank 6 are removed out of the well, and after expiration of thecalculated time for grouting mortar hardening the packer 1 and thecement bridge 22, which have been formed in the result of the groutingmortar hardening, are drilled with the use of the drill bit 18. Afterthis the formation 21 is perforated in the calculated range of depths,and the piping string 4 is lowered into the well with the shank 19having the guiding cone 23, the packer 20 and the jet pump 5 having thethrough passage 8 with the mounting seat 9 in its housing 7, all of thembeing arranged down-top on the piping string 4. Then the packer 20 isreleased, and the whole cycle of logging and hydrodynamic studies iscarried out proceeding from the results of which a decision is takenwhether to put the well into operation or to conduct additional worksfor intensifying the well production; and after this the measures forputting the well into operation may be performed.

INDUSTRIAL APPLICABILITY

This invention may be applied in the oil industry in repair andinsulating works, repair and restoration works, as well as when testingand developing wells in other industries where various media areextracted from wells.

1. The method of operating the well jet unit while carrying out repairand insulating works, which consists in that in the well, above theproducing formation roof, a drillable packer is arranged having athrough passage, the throat of the latter being closed by a check valve,the piping string is lowered in the well with a jet pump and a stingershank, which are successively arranged thereon, the said jet pump beingarranged in the housing in which a through passage with the mountingseat is made, and the said stinger shank being arranged below the saidhousing and being intended for slip connection with and disconnectionfrom the said drillable packer; then the stinger shank is connected withthe drillable packer, the check valve opens thus connecting theunder-packer area with the inner cavity of the piping string, then awell logging device on the logging cable is lowered into the wellthrough the inner cavity of the piping string, a sealing assembly beingmovably arranged on the logging cable above the said well logging deviceand being installed at the mounting seat in the through passage made inthe housing of the jet pump, in doing this the reciprocal motion of thelogging cable is ensured both at the operating and non-operating jetpump, after the well logging device has reached the interval of theproducing formation, it is installed in a fixed position, and bysupplying the working fluid to a nozzle of the jet pump several valuesof depression on the formation are created with the duration sufficientfor stabilizing the bottom-hole pressure and enabling the inflow offluids from the formation, the bottom-hole pressure and the parametersof the formation fluid are registered in this operation mode with theuse of the well logging device, after which the parameters of thephysical fields are recorded at several fixed values of the depressionon the formation while moving the well logging device along the well inthe under-packer area, and after a study program is completed, theobtained results are interpreted, and the results of such interpretationare used for the identification of the watering sources and thetechnical condition of the well, then, the well logging device with thesealing assembly are removed out of the well, and, if necessary,geo-technical measures, such as acid treatments, formation impactingwith momentary cyclic depressions—repressions, formation re-shots,acoustic impact on the formation bottom-hole area in the depressionmode, all of which are aimed at the creation of the necessaryhydrodynamic connection between the formation and the well and arecarried out with the use of the jet pump, then the study cycle isrepeated with the use of the well logging devices in the mode ofdepression on the formation, then the well logging device together withthe sealing assembly is removed out of the well, and a blocking inserthaving a through passage is dropped into the inner cavity of the pipingstring and arranged in the through passage of the jet pump housing, thesaid blocking insert being used for closing the passages for supplyingthe active medium and the medium pumped out by the jet pump and, thus,for separating the hole clearance around the piping string and thecavity inside the piping string, after this the piping string isslightly raised, thus disconnecting the whole arrangement from thepacker, closing the check valve and dividing, due to this, the wellspace into the above-packer area and the under-packer area; then agrouting mortar is pumped into the piping string and, after it reachesthe lower portion of the stinger shank, the piping string is loweredagain, the stinger shank is connected to the drillable packer and thecheck valve opens, then the grouting mortar is pumped into theunder-packer area for peening into the producing formation, then thepiping string together with the jet pump and the stinger shank areremoved out of the well, and after expiration of the calculated time forgrouting mortar hardening the packer and the cement bridge formed in theresult of the grouting mortar hardening are drilled, the formation isperforated in the calculated range of depths, and the piping string islowered into the well with a shank having the guiding cone, the packerand the jet pump having the through passage with the mounting seat inits housing, all of them being arranged down-top on the piping string;after this the packer is released, and the whole cycle of logging andhydrodynamic studies is carried out proceeding from the results of whicha decision is taken whether to put the well into operation or to conductadditional works for intensifying the well production; and after thisthe measures for putting the well into operation may be performed. 2.The well jet unit of claim 1 comprising, on the piping string, thepacker and the jet pump with the active nozzle, the mixing chamber andthe through passage with the mounting seat for arranging the sealingassembly, the said unit being provided with the transmitter andreceiver-transducer of physical fields, which is arranged in theunder-packer area on the side where the medium pumped out of the wellenters the jet pump and which is installed on the logging cable passedthrough the axial passage of the sealing assembly, the output side ofthe jet pump is connected to the area around the piping string, theinput side of the passage for supplying the pumped out medium to the jetpump is connected to the inner cavity of the piping string below thesealing assembly, and the input side of the passage for supplying theliquid working medium to the active nozzle is connected to the innercavity of the piping string above the sealing assembly, characterized inthat the said well jet unit being provided with the stinger shankintended for slip connection with and disconnection from the drillablepacker preliminary arranged in the well and made with the throughpassage and the check valve closing the throat of that passage andhaving the possibility of opening to the side of the producingformation, and the packer is made with a central passage and a shankwith the guiding cone, being arranged lower than the packer, and isarranged with the possibility of being replaced by the stinger shank,the inner diameters of the stinger shank and the shank with the guidingcone being at least 1 mm greater that the diameter of the transmitterand the receiver-transducer of physical fields, the sealing assemblybeing arranged with the possibility of being replaced by otherfunctional inserts, including a blocking insert, a pressurizing insert,a depression insert or an insert for recording formation pressurerestoration curves with the use of autonomous well instruments; and thetransmitter and receiver-transducer of physical fields being made withthe possibility of being replaced by other well instruments, including,a puncher or a device for acoustically impacting the producingformation.